Question

我没有编程经验。我试图在laravel中创建一个备份表的控制器。这些表已正确备份，但是我收到一些评论说我的代码很容易被破坏。我一直在尽力而为，但是我真的很精疲力尽，感到沮丧。 我有一个表，表中的每一行占用1到10 MB的内存。表100中的总行。最大内存量（memory_limit）设置为35 MB。什么是解决此问题的最佳方法？我真的很感谢任何建议或帮助。这是我的代码：

BackupController类

<?php
namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Illuminate\Support\Facades\Storage;
use Illuminate\Database\Events\StatementPrepared; // set the fetch mode
use Illuminate\Support\Facades\Cache;
use Carbon\Carbon;
use Illuminate\Support\Facades\Schema;
use DB;
use App\Post;
use App\User;
use App\Jobs\BackupTableJob;
use Artisan;

class BackupController extends Controller
{
    const MAX_VALUE = 35000; //kilobytes 

    public function lockTable()
    {
        // lock all tables
        DB::unprepared('FLUSH TABLES WITH READ LOCK;');
    }

    public function setQueueJob(User $user, Post $post)
    {
        BackupTableJob::dispatch($user, $post)
            ->delay(Carbon::now()
            ->addSeconds(5));
        // Artisan::call('queue:work');     
    }

    public function unlockTable()
    {
        // unlock all tables
        DB::unprepared('UNLOCK TABLES');
    }

    public function queryFetch($data)
    {
        $pdo  = DB::connection()->getPdo();
        $stmt = $pdo->prepare($data);
        $stmt->execute();
        // $stmt = $pdo->query($data);
        $results = $stmt->fetch();
        return $results;
    }

    public function create(Request $request)
    {
        $this->setPdoMode();
        $numTables = DB::select("SHOW TABLES");
        $countUserRecords = User::count();
        $countPostRecords = Post::count();

        return view('backup', compact('numTables','countUserRecords', 'countPostRecords'));
    }

    public function setPdoMode()
    {
        \Event::listen(StatementPrepared::class, function($event) {
        $event->statement->setFetchMode(\PDO::FETCH_ASSOC);});
    }

    // public function backup(Request $request, User $user, Post $post)
    public function backup(Request $request, User $user, Post $post)
    {
       $this->setQueueJob($user, $post);          
       if ($request->all()) {
           $tables = request('table');
           $output = '';     
           foreach ($tables as $key => $table) {  
               $this->lockTable();
               $show_table_query = $this->queryFetch("SHOW CREATE TABLE {$table}");
               $output .="\n" . $show_table_query[1] . ";\n";
               $this->setPdoMode();
               $single_result = DB::select("SELECT * FROM {$table}");
               $output .= $this->getTableData($single_result, $table);
               $output .= $this->cacheData($table, $output); 
           }
           if ($this->checkFileSize($output)) {
               return redirect()->route('create'); 
           }                  
        }             
        return redirect()->route('backupError'); 
    }

    // Stores the file in this location: storage/app
    public function download($output)
    {
        $dt = Carbon::now();
        $file_name = 'backup_on[' . $dt->format('y-m-d H-i-s') . '].sql';
        Storage::disk('local')->put($file_name, $output);
    }

    public function getTableData($single_result, $table) 
    {
        $this->unlockTable();
        $output = '';
        foreach ($single_result as $key => $table_val) {
            if ($table === "posts" || $table === "users") {
                $output .= "\nINSERT INTO $table("; 
                $output .= "" .addslashes(implode(", ", array_keys($table_val))) . ") VALUES(";
                $output .= "'" . addslashes(implode("','", array_values($table_val))) . "');\n";
            }  
        }
        // $output .= $this->cacheData($table, $output);   
        return $output;
    }

    public function checkFileSize($file)
    {
        $file_size = strlen($file);
        // convert bytes to kilobytes 
        $file_size = round($file_size / 1024, 0, PHP_ROUND_HALF_UP);
        if ($file_size <= self::MAX_VALUE) {
            $this->download($file);
            return true;
        } 
        return false;               
    }

    public function cacheData($table, $data)
    {
        // $table = $table;
        $start = microtime(true);
        $data = Cache::remember('table', 10, function() use ($table){
            return DB::table($table)->get();
        });
        $duration = (microtime(true) -$start) * 1000;

        \Log::info("From cache: " . $duration .' ms');
        return $data;
    }
 }

BackupTableJob类

<?php

namespace App\Jobs;

use App\User;
use App\Post;
use App\Http\Controllers\BackupController;
use Illuminate\Http\Request;

use Illuminate\Bus\Queueable;
use Illuminate\Queue\SerializesModels;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;

class BackupTableJob implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable; //SerializesModels;

    protected $user;
    protected $post;

    /**
     * Create a new job instance.
     *
     * @return void
     */
    public function __construct(User $user, Post $post)
    // public function __construct()
    {
        $this->user = $user;
        $this->post = $post;
    }

    /**
     * Execute the job.
     *
     * @return void
     */
    public function handle()
    {
        // $this->user->save();
        // $this->post->save();
    }
}

Answer 1

您不需要使用PHP处理该数据。您可以在laravel中简单地使用原始SQL查询：

SELECT *
INTO tableToBeBackedUp
FROM currentTable;

在Laravel中创建备份控制器

1 个答案: